Reader for reading magneto-optical characters, with the options of printing them or storing them

Abstract

A reader for reading magneto-optical characters, with the options of printing them or storing them. A track is provided for driving a check from an inlet plate (T1) over various portions of path (T2, T3 and T4). Wheels (G1 and G2) are provided beneath the path, and may be motor driven. Above said wheels there are heads (TM1 and TM2) respectively for premagnetizating and reading CMC7 characters. Each head is mounted on one arm of a corresponding bell crank (L1, L2) which cranks are pivoted to a frame at their corners (L10 and L20). The other arm (L12 and L22) of said bell cranks are resiliently urged by springs (L15 and L25) mounted on an actuator rod (AC) which is itself driven by an electromagnet (EM2). It has turned out that such an assembly ensures effective transducer operation of the heads (TM1 and TM2) for reading CMC7 characters.

We claim: 
     
       1. In a magneto-opical character reader for reading characters such as CMC7 characters, the reader comprising a path suitable for receiving and driving a document carrying such characters through predetermined positions, a premagnetization transducer for premagnetizing said characters, a read transducer for reading said characters, and electronic control and processing means connected to said transducers, the improvement wherein said path for receiving the document includes wheels having axes fixed relative to a frame, and said transducers being mounted opposite a respective one of said wheels and being controllably and resiliently urgeable towards said respective wheel. said electronic control and processing means including read means comprising:   analog amplifier means having an anti-saturation gain characteristic;   first comparator means possessing hysteresis and having a signal input connected to the output of said analog amplifier means, and a reference input receiving a reference voltage close to zero volts, an output, and an output to said reference input to provide said hysteresis;   second, fast-acting comparator means having a signal input connected to the output of said analog amplifier means, a reference input connected to the output from the first comparator via a capacitative circuit including a diode, and an output connected to said input via a diode link; and   logic means for providing a logic signal representative of the characters read on the basis of the output signals from said two comparator means.   
     
     
       2. A reader according to claim 1, wherein each transducer is mounted at the end of one arm of a corresponding L-shaped crank, each of said cranks being pivoted at its angle to the frame, and the ends of the other arms of said cranks being controlled via respective resilient means by an actuator rod which is controlled by an electromagnet. 
     
     
       3. A reader according to claim 2, wherein the actuator rod is itself provided with resilient return means operating against the electromagnet. 
     
     
       4. A reader according to claim 1, wherein said analog amplifier means comprise, connected in series: a low-noise preamplifier;   a mains rumble filter;   an amplifier;   a background noise limiter circuit; and   an amplifier having a non-linear, anti-saturation gain characteristic.   
     
     
       5. A reader according to claim 1, wherein said logic means comprise: a first bistable acting as a storage cell, including a clock input controlled via a NAND gate from the outputs of said first and second comparator means, and a reset to zero input controlled by the output from said first comparator means; and   a second bistable connected as a divide-by-two circuit, controlled by the output from the first bistable, and providing a logic signal representative of the characters read.   
     
     
       6. A reader according to claim 1, further including electronic means suitable for performing a commercial transaction, together with printer means and control logic means, the reader including the improvement whereby said control logic means are arranged to provide, after a commercial transaction has been performed, a sequence of commands suitable for reading the magneto-optical characters on a check and for printing the amount of the transaction on said check. 
     
     
       7. A reader according to claim 6, wherein printing is performed on the check in columns using a special character set. 
     
     
       8. A reader according to claim 6, wherein the logic control means also include means for printing a client ticket and a shopkeeper's journal. 
     
     
       9. A reader according to claim 6, wherein the logic control means are additionally suitable for providing a local or distant memory with electrical signals representative of the characters read on the check and of the characteristics of a transaction, thereby simplifying bank processing of said checks.